As it transpired, the Wabco 252FT was the last in a long line of C-series Tournapulls, and was an excellent machine, but debuted at the wrong time. It was one of the last elevating scrapers ever manufactured by Wabco. By Richard Campbell.
LeTourneau-Westinghouse/Wabco had a long history with manufacturing elevating scrapers, and through its partnership with Hancock, offered some of the first elevating scrapers to be produced on a commercial scale, the first being the matching of a Model D Tournapull with a Hancock 10E2 elevating scraper in 1960.
This proved such a success that LeTourneau-Westinghouse began investigating the use of other Hancock elevating scrapers with the larger Model C and B Tournapulls in their range.
At first, the Hancock model 216 was offered as an option for use behind the Model C Tournapull.
This was rated at around 21 cubic yards and featured electric drive of the two elevator motors.
Again the match proved to be a success and so began LeTourneau-Westinghouse’s long association with the elevating scraper.
The subject of this month’s article, the Wabco 252FT, was first introduced in 1975.
It was not derived from the single engined Wabco 222G, but in fact it was based on the very rare Wabco 222FT which was only manufactured for two years, 1972 thru 1974.
What started out as basically an experimental machine, the twin powered 222FT was put into limited production and featured a 25 cubic yard bowl and twin GM 8V-71T engines putting out a combined 640 flywheel horsepower.
Transmissions were the Allison VCLBT 5860, six-speed with variable input converter and a hydraulic retarder.
In a distinct about turn from previous Wabco elevating scrapers, the elevator was hydraulically driven, a feature that was passed on to the 252FT and larger 353FT.
Ready for action, a 222FT tipped the scales at 44 tons.
It should also be noted here that the model 222FT was the very first Wabco scraper to ever feature planetary drives in the tractor unit.
Although the 222FT was not a big seller, the obvious potential was there for all to see.
Caterpillar did not (and still don’t), offer a twin powered elevating scraper in the 25 cubic yard class.
In 1974, Wabco undertook a fairly extensive redesign of the tractor and scraper units producing the all-new model 252FT (series CPA17-A).
This featured the same GM/Allison drive train of the 222FT (including the horsepower output) but replaced the VCLBT5860 transmission with the Allison VCLT5860.
The tractor unit was considerably modified and beefed up.
Adjustments to the scraper raised the capacity to 27 cubic yards and the entire elevator system was streamlined somewhat and had the hydraulic drive motor relocated to the right hand side of the elevator frame (it was on the left on the 222FT).
A fairly extensive rear spillguard was also added as standard equipment which kept debris flung up by the elevator loading action from damaging rear engine components.
Overall weight of the 252FT was approximately 45 tons and the machine was recognized as having an excellent power to weight ratio.
Wabco’s torque proportioning differential was standard equipment in the tractor and scraper and this, combined with the variable input converter in the transmission, maximized traction and kept wheel spin to a minimum when loading.
Wabco had done away with electric steering in the late 1960s, so the 252FT had the now familiar two-cylinder hydraulic steering system (which Wabco had first introduced on their model C222F).
For a medium capacity motor scraper, the 252FT could move its 76 ton loaded bulk along quite smartly at around 30 mph.
For braking, wedge-type air over hydraulic actuated shoe brakes were utilized.
The bowl’s elevator contained fourteen flights and was driven by a two-speed, reversible vane type hydraulic motor.
Loading speeds were 127 feet/minute in low and 254 feet/minute in high.
Ejection was by sliding floor and doze out ejector.
An optional set of cutting edge teeth were available to enable easier loading of densely packed material.
A well appointed ROPS cab was usually supplied as standard equipment although an open ROPS structure could be fitted for service in the tropics.
Since LeTourneau first began manufacturing motor scrapers in 1937, they have always placed the operator in the centre of the tractor unit.
As the 252FT did not feature any form of suspension, this, combined with the air suspension seat, always gave a better quality ride than most of it’s competitors (take it from me – Author).
The Wabco 252FT was marketed at mid-sized contractors and mining operators where self loading was a big plus.
Unfortunately for Wabco, the world was headed for a recession in the late 70s and demand for motor scrapers of all sorts simply dried up.
Wabco was forced to close several of its manufacturing facilities in order to maintain liquidity and the model 252FT was one of the casualties, being discontinued in 1980 after only five years in production.
Even significant downsizing could not save Wabco’s earthmoving division with the company folding around 1982 with the bulk of what remained being sold to Dresser Industries.
Exact production numbers for the model 252FT are unknown but are unlikely to exceed 150 units.
Postscript: The model 252FT also spawned a twin powered conventional bowl machine known as the model 259FT.
Utilizing the same tractor unit as the 252FT, but with an all-new bowl, the 259FT is a very rare beast indeed with less than 100 manufactured – and there is one in New Zealand!
The New Zealand Connection
There are more active Wabco 252FTs alive and well in New Zealand than were ever imported into Australia!
Principal users of the type are Goodman Earthmovers and Dempsey & Wood, both of which have well maintained fleets driven by excellent operators.
Some of these machines have now been repowered with the higher output GM 8V-92T engine which is also a little more economical than the original GM 8V-71T.
Both companies deserve a round of applause for keeping history alive!
For the model collector
Regrettably, models of the 252FT and its predecessors are non-existent, for what reason the author is unsure.
It probably has something to do with product licensing, an irritating excuse if ever there was one.
However, if you possess a modicum of modeling skill, you can actually build one of these machines using two of the old Lindberg/Heller Wabco 333FT kitsets and a bit of scratch building.
The Lindberg/Heller kit is to 1:60 scale but the dimensions work out about right for a 252FT in 1:50 scale.
Brief Specifications – Wabco 252FT
Engines: 2x General Motors 8V-71T (N75) V8 two-cycle diesel engines rated at 327 flywheel horsepower at 2100 rpm each
Transmissions: 2 x Allison VCLT5860 6-speed variable input powershift transmissions with an extra loading range
Top Speed: 30 mph
Tyres: 33.25×35 E-3 (32 ply on tractor, 38 ply on scraper)
Brakes: Air over hydraulic actuated wedge, shoe type
Steering: Full hydraulic with 90° steer in either direction
Turn Circle: 35’ 8”
Capacity: 27 cubic yards
Operation: Fully hydraulic with 2-speed elevator drive
Elevator Flights: 14
Height: 13’ 6”
Operating Weight: 44.5 tons (empty), 76.5 tons (loaded)